A scientific review of present knowledge of drugs of abuse, especially South American, comprising much hitherto unpublished information from field observations of the three investigators and their critical evaluation of the body of information available in the literature available in nine languages. The aim of the review is to provide a readily available summary of our present knowledge of aboriginal uses of drugs in order to increase the practical efficiency of sociological, legal and health aspects of misuse and abuse of drugs in our society and to provide hints as to better methods of arriving at basically pertinent data for effective drug use control. Such a transcultural study has never been prepared and should provide governmental and legislative officers with useful guidelines. Representing the culmination of many years of field, laboratory and library research by the three investigators, the summary will be a book-length report.